JPH05151621A - Optical recording card - Google Patents

Abstract

PURPOSE:To improve reliability for recorded information by having a large number of a linear recording part parallel to each other in a recording area on a card substrate, forming a pit on a specific part of the linear recording part and recording the information. CONSTITUTION:An optical recording card is constituted of a shape memory resin plate with the flat linear recording part, and since the pit 11 shape of a projecting shape or a recessed shape restoring by being heated to a transition temperature or above is stored in a roughly central part except, both end parts of the linear recording part, when a laser beam is converged on a pit shape recording part, the converged part is heated to the transition temperature or above and the original pit shape of the projecting shape or the recessed shape is restored. On the other hand, the pit is not formed even when the laser beam stands still at any of these both end parts.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an optical recording card.
More specifically, the present invention has a large number of linear recording portions parallel to each other on a card-shaped recording layer surface, and selectively records a laser beam on a specific portion of the recording portion to form a pit for recording. Then, the present invention relates to an optical recording card for discriminating the presence or absence of a pit by a reflected beam obtained by scanning a laser beam along the linear recording portion and reading the record.

[0002]

2. Description of the Related Art Such a card is well known in the prior art, and is generally formed by laminating a thin recording layer such as a vapor deposition film of metal or dye and a protective layer on a transparent base sheet and forming a transparent substrate. A laser beam is focused on the recording layer from the material sheet side to heat the recording layer, and by this heating, the thin recording layer is evaporated or modified to form pits for recording.

Since the card is generally quadrangular and therefore the recording area is also generally quadrangular, a large number of linear recording portions parallel to each other are provided in the recording area, and the laser beam for recording is linear. Scanning is performed along the recording area, and after the light collecting area reaches the end of the recording track line, the light is moved to the next linear recording area.

The same applies to the case of reading recorded information from a recorded card. A laser beam for reading is scanned along a linear recording portion, and the recorded information is determined from the difference in the intensity and phase of the reflected light beam based on the presence or absence of pits. To read. The laser beam for reading also reaches the end of the linear recording portion and then moves to the next linear recording portion.

[0005]

By the way, during the recording or the reading, the laser beam is intermittently moved between the linear recording portions, and when the laser beam is not in operation, both ends of the linear recording portion are not moved. It is stationary on either side. If such a stationary state continues for a long time, the recording layer composed of the above thin film may be evaporated or denatured, and erroneous information may be recorded, which impairs the reliability of the recorded information and a recording / reading device (reader / writer). ) Of the auto-tracking mechanism, auto-focus mechanism, etc. may cause malfunctions.

Therefore, the present invention provides an optical recording card in which erroneous information is not recorded at both ends of the linear recording portion in both recording and reading, and the recorded information is highly reliable. The purpose is to

[0007]

That is, the present invention has a large number of linear recording portions parallel to each other in a recording area on a card substrate, and a laser beam is selectively focused on a specific portion of the linear recording portions. In the optical recording card which reads the recorded information by illuminating and forming pits to record information and then determining the presence or absence of pits by the reflected light obtained by scanning the laser beam along this linear recording portion, The shape recording part is made of a flat shape memory resin, and the convex or concave pit shape that is restored by being heated to the transition temperature or more is stored in the substantially central part excluding both ends of the linear recording part. Characterize.

In such technical means, the "shape memory resin" means that a convex or concave pit is formed at a temperature equal to or higher than the transition temperature specified according to the type of resin, and the transition temperature is maintained as it is. By cooling below, even if the pit disappears due to deformation in the cooled state, it is one that restores the original pit shape by being heated again to the transition temperature or higher. For example, polynorbornene resin (transition temperature about 50 ° C.) or the like can be used.

And, in the optical recording card according to the present invention,
A shape memory resin that stores such convex or concave pits at approximately the center of the linear recording area where the laser beam is placed at rest during recording or reading, except for both ends, is formed at a temperature lower than the transition temperature. It is crushed to disappear and used as a flat linear recording area. When the laser beam is focused on the pit-shaped recording portion of such a recording layer, the original convex or concave pit shape is restored even if this focused portion is heated to the transition temperature or higher. Information is recorded.

On the other hand, the pit shape is not recorded at both ends of the linear recording portion, so that even if the laser beam is stationary at either end, no pit is formed, and erroneous information is recorded. Recording is prevented.

The recording area according to the present invention is provided in parallel with the linear recording portion, and alternately with the linear recording portion, extending to both ends of the linear recording portion where the pit shape is not stored. It is preferable to have an associated tracking guide. This tracking guide indicates the scanning direction of the laser beam at the time of recording or reading.
The shape memory resin may be formed of a groove.

The shape-memory resin that stores the pit shape and is made flat is used as a recording area by adhering onto a suitable card substrate. The recording area may cover the entire surface of the card substrate or may be provided in a part thereof. As the card substrate, for example, polycarbonate resin, acrylic resin, polyester resin, polyvinyl chloride resin, polyolefin resin, polyurethane resin, epoxy resin, polystyrene-polycarbonate mixed resin, etc. can be used. Further, the card base and the shape memory resin can be adhered by using an adhesive such as an epoxy adhesive, an acrylic adhesive, a urethane adhesive, a polyester adhesive, or the like.

In order to efficiently utilize the thermal energy of the laser beam during recording and to improve the sensitivity of the linear recording portion, it is desirable to provide a light absorbing layer on the linear recording portion. As the light absorbing layer, for example, T
_{e-C, CS 2, Pb} -Te-Se, can be used a thin film such as TeO _X, it can also be used cyanine dyes, coating film such as Ni-stabilized cyanine dye. It is also possible to provide a transparent protective layer on the recording area or on the light absorbing layer.

[0014]

According to the invention described in claim 1, the linear recording portion is composed of a flat shape memory resin, and is restored by being heated above the transition temperature to substantially the central portion excluding both ends of the linear recording portion. Since the convex or concave pit shape is stored, when the laser beam is focused on the pit shape recording area, the original convex or concave pit even if the focused area is heated to the transition temperature or higher. It restores its shape, while it does not form pits when the laser beam rests on either of these ends.

[0015]

EXAMPLE As shown in FIG. 4A, a shape memory resin plate 1 made of Sable A-60 (polynorbornene resin, transition temperature about 50 ° C.) manufactured by Nippon Zeon Co., Ltd. was projected by pressing a nickel stamper at 120 ° C. Both the part and the recess were molded and cooled to room temperature. Among them, the convex portion is a large number of pits 1 with a width of about 3 μm and a length of about 6 μm arranged on a large number of parallel straight lines.
1. Comprising 1 and both ends 1a of this straight line (length about 500 μm)
Not provided in. The recess has a linear width of 2.5 which is parallel to the pit row and which is arranged alternately with the pit row.
The grooves 12 have a depth of 2 μm, a depth of 2 μm, and a pitch of 12 μm, and extend further from both ends of the pit row to reach both ends of the shape memory resin plate 1.

Next, as shown in FIG. 4B, at normal temperature, the pit row 11 was pressed to crush and eliminate the pit shape.

The memorized shape memory resin plate 1 is attached to a base sheet 2 made of an acrylic sheet manufactured by Nitto Denko Corporation, and a Te-C vapor deposition film 3 is formed on the surface of the shape memory resin plate 1. Laminated by the method. Finally, a transparent polycarbonate 4 was laminated on the Te-C vapor deposition film 3 and the whole was punched into a card shape (85.5 mm × 54 mm) to obtain an optical recording card. A plan view of the obtained optical recording card is shown in FIG. 1, and a sectional view taken along line XX is shown in FIG. As can be seen from the figure, in the recording area composed of the shape memory resin 1, there are tracking guides composed of a large number of grooves 12 parallel to each other, and the tracking guides reach both ends 1a of the recording area. ..

This optical recording card was recorded by an existing reader / writer. Figure 1X- of an optical recording card when recorded
A cross-sectional view taken along the X-ray is shown in FIG. As can be seen from the figure, pits 1 are selectively formed on the laser beam.
1 has been restored.

The optical reader card thus recorded was read using the same reader / writer. There was no misinformation and no malfunction of the reader / writer.

[0020]

According to the first aspect of the present invention, when the laser beam is focused on the pit-shaped recording portion, it has a convex or concave shape even if the focused portion is heated to the transition temperature or higher. The pit shape is restored, while pits are not formed even when the laser beam is stationary at either of these two ends, there is no recording of erroneous information due to the stationary laser beam, etc. There is no malfunction, and thus the reliability of recorded information is dramatically improved.

[0021]

[Brief description of drawings]

FIG. 1 is a plan view of an optical recording card according to an example.

FIG. 2 is a sectional view taken along line XX of FIG.

FIG. 3 is a sectional view taken along line XX of FIG. 1 after recording.

FIG. 4A is a cross-sectional view in the process of manufacturing an optical recording card. B is a sectional view of the optical recording card during the manufacturing process.

[Explanation of symbols]

 1 Shape Memory Resin Plate 11 Pit 12 Groove 1a Both Ends of Linear Recording Site 2 Base Material 3 Light Absorbing Layer 4 Protective Layer

Claims (1)

[Claims] 1. A recording area on a card substrate has a large number of linear recording portions that are parallel to each other, and a laser beam is selectively focused on a specific portion of the linear recording portions to form a pit to form information. An optical recording card for recording and reading recorded information by discriminating the presence or absence of pits by a reflected light beam obtained by scanning a laser beam along the linear recording portion, wherein the linear recording portion is formed from a flat shape memory resin. An optical recording card characterized in that a convex or concave pit shape that is restored by being heated to a transition temperature or higher is stored in substantially the central portion except both ends of the linear recording portion.